Foundations



H. vW. TONILINSON.

METHOD 0F BUILDING FOUNDATIONS.

APPLICATION FILED OCT. 21.1918.

Patented Nov. 4, 1919.

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METHOD OF BUILDING FOUNDATIONS.

Specification of Letters Patent.

Patented Nov. d, 1919.

Applicationried October 21, 1918. Serial No. 259,123.

T 0 all whom t may concern.'

Be it known that I, HENRY lV. ToMLIN- soN, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a new and useful Improvement in Methods of Building Foundations, of which the following is a specilication.

My invention relates to certain new and useful improvements in the method of building foundations, and is fully described and explained in the specification and shown in the accompanying drawings, in which Figure l is a transverse section through a wall, the foundation for which is built in accordance with my invention; Figs. 2, 3, il, and 5, are simil-ar sections through modified forms, all built in accordance with the same general method, but havin@a certain advantages which will hereafter appear.

method was primarily designed `for building the foundation of a very large wall of the type such as is commonly erected around penal institutions, and, in practical' use for ythat particular work,fit' has proved highly satisfactory. In this particular work, it is desirable to carry the foundation well underground in order to prevent the possibility of tunnelingy under "the wall.

The common practice is to dig -adeep trench,

of the width of the foundation slab or footing, and necessarily to excavate the sides of the trench back at such angles` as the earth can occupy without caving in. The footing is then customarily placed at thebottom of the'trench so constructed, the wall isverected, and the vtrench is then filled in above the footing. This usual method requires a great deal of expensive excavating, and it requires the presence of a spoil bank of considerable size which interferes with the progress 0f the erection of the wall. Furthermore,'it results in a considerable body of kloosened earth on the two sidesV of the wall into which water enters freely for some time after the wall is completed, and, in this manner, the disad-vantageousresults of frost are accentuated. Furthermore, in the case of east and west walls, the earth on the north side of the wall will remain frozen longafter that on the south side has thawed out, and in this way unequal pressure above :the yfooting is created against the side of the wall proper with sults.

My present method is designed to avoid the difficulties above suggested, and to afford a method of building the foundations which is cheaper, more expeditious, and which produces a better foundation than has heretofore been customary.

In the practice of my invention, I first dig, with an ordinary ditching machine of the type commonly in use, two parallel ditches comprehending the two cross-sectional rectangular areas 6, 7, 8, and 9, in Fig. 1. I remove the earth by successive cuts at a steep angle, whereby any given cross-section of the trench is completed for its full depth at approximately the same time. These cuts approximate the vertical, although some of the ditching machines work at an angle of about 45. Machines for doing this digging are well known and work at a low cost and at considerable speed, and they are usually provided with conveyers so that the material excavated can be loaded immediately into wagons for removal. As fast as the ditching machine advances cutting the trench to its full depth, it is followed up by the concrete mixer, and the concrete is poured directly into the ditch, so as to form two walls up tothe level of the base of the footing slab, the level of these walls being indicated by the line 10,

obvious undesirable rell, and suitable anchoring means being in-v serted, if desired. Thus it will be seen that the digging of /the trench progresses horizontally by a series of steep cuts, each cut being immediately filled with concrete approximately as soon as it is made.

A considerable number of incidental advantages are attained in this portion of the work. Obviously, forms are unnecessary under normal circumstances, The flexibilg ity of the ditching machine is such that the depth of the trench can be varied as the work progresses so that the wall in all cases goes down to a good firm foundation. In case soft ground is encountered, the relative advantages are even greater, because after the ditching machine has passed through fairly soft ground, the walls usually do not cave in immediately, but are self-sustaining for a brief period. In the use of my method, the .concrete is lled in so rapidly ing them simply caves into the ditch and is I taken out by the ditching machine, leaving hollow cavities in the walls of the trenches i which the concrete properly iills up, thus getting a greater degree of stability at no `additional expense from a pocket which would ordinarilyA seriously interfere with the work. In every case the scores left on the earth'by the ditching machine produce irregularities in the concrete which make a very iirm bond between the walls and the earth in which they are located.

chine has passed, and get the concrete in so quickly as to make -it unnecessary either to pump ork put in coil-'er dams or retaining walls. As soon as the concrete is poured, these temporary plates can be withdrawn, the concretel comes into immediate contact Vwhile still soft with the earth.

As soon as the vertical walls, indicated yin the drawings by the characters 12 and 13,

are poured, the remainder of the excavation can be done, this consisting of the earth represented by the cross-sectional rectangle 6, 7, 14, 15. This can be done in any desired manner, is relatively small in quantity, and the earth thus removed can usually be profitably .employed in refilling. When` this is done, the slab 16 is poured, and for this work, as well, no forms are necessary, unless the ground is very soft in which case a temporary support may be necessary along the outer edges Where there may have been a slight caving in on top of the finished walls 12 and 13. This completes the foundation, and the wall lsection can be erected. thereon in the usual manner. The foundation produced is 0f very great strength, more particularly because the body of earth between the side walls 12 and 13 and beneath the footing 16 is confined thereby, and even if inherently of very soft material, is incompressible and, therefore, acts as a perfectly solid body. It is furthermore to be noted that Vthis body of earth hasbeen undisturbed by the operation and is, therefore, not liableto settle. Furthermore, the foundation has its greatest support at the sides where it is most needed if any lateral pressure is to be encountered. lThe process herein described v can be carried'on even in the coldestweather place of coiffer dams.

because the trenches can be illed up with concrete before the sides thereof have time to freeze, and the concrete is thereafter protected by the undisturbed earth banks. These walls, when completed, prevent frost and water from getting under the footing slab 16,'so that this can be safely located very close to the surfaceJ of the ground. If openings are required through the walls, the frames therefor canbe placed in position immediately after the passage of the ditching machine and before the concrete 1s poured. Obviously, if additional lateral support is required, suitable lateral spaces can be cut in the sides of the trenches after the ditching machine has passed, and when vthe concrete is poured there will thus be.

formed piers or pilasters.

Figs. 2 and 3 illustrate modifications in the construction in which the footing slab 16 'is replaced by @an arch, `that in Fig. 2 being preferably built of masonry and that in Fig. 3 being of masonry or concrete. In the form shown in Fig. 4, the w-all erected upon the foundation is to one side, such as might be employed in a retaining wall.

In any or all of the structures thus formed, the material between the Walls 12 and 13 can be excavated so as to forma tunnel, and my method thus forms a peculiarly simple and cheap method for building tunnels. If

desired, the same general method can be employed in the construction of building walls, basements, and the like, in which case the walls will be built -as described, and the space between them thereafter excavated. In case very thick underground walls yare required, beyong the capacity ofthe ditching machine, it is possible to build twoparallel lwalls, and when the :concrete therein has set, to excavate the intermediate space and fill that alsov with concrete. In this way,

in of soft ground, and can thus be used In the form of construction shown in Fig. 5, a series of parallel trenches are cut as described and each is filled in with concrete, the slab being built thereon. By this means,

Vany degree ofsupport can be afordedfor the slab, and extensive and very firm foundations can be built with great rapidity. This method is desirable in the building of foundations for very heavy walls, or for floor foundations where heavy machinery is to be carried, and it believed to be especially advantageous in the rapid construction of concrete emplacements for artillery.

I realize that considerable variation is possible in the details of this construction without departing from the spirit of my in-- vention; therefore I do not intend to limit myself to the specific form herein shown and described except as pointed out in the following claims, in which it 1s my intention to claim all the novelty inherent in the construction as broadly as is permitted by the state of the art.

What I claim as new and desire to secure by Letters Patent is l. The method of constructing foundations for walls which consists in excavating a trench by removing the earth progressively along the trench and by successive cuts at ka steep angle, whereby any given cross-section of the trench is completed for its full depth at approximately the same time, filling each cut with concrete as it is excavated, permitting the concrete to set in immediate contact with the undisturbed earth sides of the trench, and erecting a wall the-reon. l

2. The method of constructing foundations or walls which consists in excavating a trench by removing the earth progressively along the trench and by successivefcuts at a steep angle, whereby any given cross-section of the trench is completed for its full depth at approximately the same time, and before the walls of each cut have had time to cave in, filling each cut with concrete, permitting the concrete to set in immediate contact with the undisturbed earth sides of the trench, and erecting a Wall thereon.

3. The method of constructing foundations for walls which consists in excavating two parallel trenches by removing the earth along the trenches by successive cutsI at a steep angle, whereby any given cross-section of the trenches is completed for its full depth at approximately the same time, lilling the same with concrete and permitting the concrete as they are excavated to set in immediate contact with the undisturbed earth sides of the trenches, a section of undisturbed earth being left between the trenches, and after the concrete in the trenches has set, laying across the two walls formed thereof a slab supported by and in contact with the undisturbed earth therebetween, and erecting a wall thereon.

4. The method of constructing foundations for walls which consists in excavating two parallel trenches, that is to say, by removing the earth progressively along the trench by successive outs at Ia steep angle, wher-eby any given cross-section of the trench is completed from top to bott'om substantially rat the same time, illing each cut with concrete as they are excavated, leaving a section of undisturbed earth between the' trenches, `and after the concrete in the trenches has set, laying a sla'b across the two walls formed thereof and in contact with and resting upon the undisturbed earth, and erecting a wall thereon.

In testimony whereof, I have hereunto set my hand this 10th day of October 1918.

HENRY W. TOMLINSON Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

